Phonon Donating Material for Indirect Bandgap Absorption
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Solution Overview
Problem
Indirect bandgap semiconductor materials, such as silicon, exhibit reduced optical absorption and emission efficiencies due to the requirement of multi-particle interactions for radiative processes, leading to lower device output and increased device size, weight, and cost, which is undesirable for portable and flexible optical devices.
Innovation Solution
A semiconductor device incorporating a non-monolayer phonon donating material structurally connected to an indirect bandgap material to generate and deliver phonons of specific frequencies, facilitating increased absorption and emission of photons, thereby enhancing optical efficiencies without the need for thicker materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a thicker silicon layer is used to increase the probability of phonon generation, then optical absorption efficiency is improved, but device size, weight, and cost increase
Solution Approach 1:
The patent introduces a phonon donating material as an intermediary component that generates and delivers phonons to the indirect bandgap material. This mediator enables efficient phonon supply without requiring increased thickness of the silicon layer, thus improving optical absorption efficiency while maintaining lightweight device characteristics.
Solution Approach 2:
The patent changes the phonon frequency parameter by selecting a phonon donating material with a specific phonon frequency that matches the requirements of the indirect bandgap material. This parameter optimization enhances the probability of phonon-assisted radiative transitions without increasing device thickness or weight.
2Productivity
If a thicker silicon layer is used to increase the probability of phonon generation, then optical absorption efficiency is improved, but device complexity increases
Solution Approach 1:
The phonon donating material serves as a simplified intermediary that directly provides phonons to the indirect bandgap material through structural connection. This approach is less complex than manufacturing and mounting thicker silicon layers with special apparatus, while achieving the same or better optical absorption efficiency.
Solution Approach 2:
The patent creates a composite structure combining the indirect bandgap material with the phonon donating material. This composite approach integrates multiple functions (photon absorption, phonon generation, and phonon delivery) into a single unified structure, reducing overall device complexity compared to using thick silicon layers with external mounting systems.
3Productivity
If more silicon is used to increase the probability of phonon generation, then optical emission efficiency is improved, but material cost increases
Solution Approach 1:
The phonon donating material acts as an external phonon source that donates phonons to the indirect bandgap material. This intermediary approach eliminates the need to increase silicon quantity, as the phonon donating material provides the necessary phonons for efficient radiative transitions, thereby improving optical emission efficiency without increasing material consumption.
Solution Approach 2:
The patent optimizes the phonon frequency parameter of the donating material to match the requirements of the indirect bandgap material. This parameter matching maximizes the efficiency of phonon-assisted radiative transitions, achieving high optical emission efficiency with minimal material quantity.
4Adaptability or versatility
If monolayer materials are used to create flexible devices, then device flexibility is improved, but optical absorption efficiency decreases
Solution Approach 1:
The phonon donating material serves as a mediator that compensates for the reduced phonon generation capability of monolayer indirect bandgap materials. By providing an external phonon source, the system achieves efficient optical absorption despite the thin, flexible monolayer structure, thus maintaining both flexibility and optical performance.
Solution Approach 2:
The patent creates a composite structure combining monolayer indirect bandgap material with phonon donating material. This composite approach enables the device to maintain the flexibility advantages of monolayer structures while achieving high optical absorption efficiency through the phonon donation mechanism, resolving the trade-off between flexibility and performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in higher photon absorption and emission rates, enabling thinner, lighter, and more portable semiconductor devices with improved efficiency, suitable for various applications including solar cells and lasers, while maintaining or approaching the efficiency of bulkier devices.
Implementation Method 1
to generate phonons, the phonons having a frequency that facilitates in the indirect bandgap material the absorption or emission of photons
Implementation Method 2
to deliver the phonons to the indirect bandgap material
Implementation Method 3
the absorption or emission of photons of a desired set of wavelengths
Implementation Method 4
the absorption or emission of photons of a desired set of wavelengths
Data Source
AI summary
A semiconductor optical device is comprised of a phonon donating material structurally connected to an indirect bandgap material to improve absorption and emission of light in the indirect bandgap material. An excitation energy source provides excitation radiation to the semiconductor optical device to excite electrons in the semiconductor optical device. Phonons from the phonon donating material present in the indirect bandgap material provide a mechanism for increased rates of electron-hole generation and recombination, and electrical leads provide an electrical connection to the semiconductor optical device.